1. Structure of the Earth Chemical Composition
Earth is divided into 3 layers: crust, mantle, core
Based on compounds that make up each layer
Less dense elements & compounds - crust & mantle
More dense elements & compounds - core
Separates by composition & density

2. The Crust 2 Types – Continental & Oceanic
Less than 1% of Earth’s mass & volume
Both share common elements such as: O, Si, Al
Oceanic crust has 2x as much Fe, Ca, Mg
The amount and combination of the elements in oceanic crust create minerals that are more dense than those in the continental crust.

3. Oceanic crust is thinner AND denser than continental crust
Oceanic crust is thinner AND denser than continental crust. Continental ~2.7g/cm3 Oceanic ~ 2.9g/cm3 (made of granite) (made of basalt)
The deepest hole ever drilled into the continental crust was in the Kola Peninsula in Russia in 1984.
It was 12,226 meters deep! (Mt Everest is only 8,850 M high so the hole is 3,376 meters deeper than Mt Everest is high!)
Because the temperature of the crust increases with depth, it is impossible to drill much deeper into the crust.

4. Element Types General distribution by volume (Earth)

5. Element Types Distribution within earth’s crust only

6. Do Now: Compare and contrast the 2 types of crust. What are their names? Compare their densities? What are they made of? (Top 4)

7. The Mantle Located between the crust and the core
Most of Earth’s mass & volume is located in the mantle (67% & 83% respectively)
Only physical observations of mantle are when mantle rock is uplifted to the surface (land or ocean floor)

8. The Core Extends from below the mantle to the center of the Earth
Made of mostly Fe with some Si & Ni
Approx. 33% of Earth’s mass & 16% volume

9. Physical Structure of Earth– 5 Layers
Lithosphere means “rock”
made up of 2 parts
Crust
Rigid upper part of the mantle
Divided into pieces called tectonic plates
Approx 0-100km
Approx 1.57% volume
The average depth is used to calculate the distance from the surface of the earth to the center which is approximately 6,380km.
When constructing the model, label according to the book and ADD that the avg depth is 148km.

10. Tectonic plates – a block of lithosphere that consists of the crust and the rigid, uppermost part of the mantle.
Lithosphere- Contains the crust, rigid upper part of the mantle & tectonic plates that seem to fit like a jigsaw puzzle pieces.

11. Asthenosphere means “weak”
Solid rock that flows very slowly
Upper part of mantle
Plastic layer of the mantle
-“malleable” soft – bendable
Pieces of the lithosphere move on top of the asthenosphere
Approx km
Approx 9.42% volume

12. Mesosphere means “middle”
Magma layer
Strong, upper part of the mantle
Between asthenosphere and core
Approx 700-2,885km
Approx – 34.30% volume

13. Mantle/Asthenosphere/Mesosphere Convection
Convection currents from the mantle/mesosphere turn clockwise or counter clockwise
This energy moves the asthenosphere
As the asthenosphere moves, blocks of lithosphere also move, bring tectonic plates along for the ride

14. Charles Hapgood Crust Displacement Theory
Theory states that lithosphere is not separate pieces that slowly move independently of each other and the rest of the Earth, but move as one piece.
Supported by Einstein
Supported by age of Antarctic ice
Supported by discovery of flash frozen animals (wolley mammoth)
_earthchanges33.htm

15. Core – 2 parts Outer Core Inner Core Liquid iron layer of the core
Approx 2,885-5,155km
Approx – 35.64% volume
Inner Core
Solid iron layer of the core
Approx 5,155-6,371km
Approx 19.09% volume

16. Magnetic Field
The combination of a liquid iron (mostly) outer core which is moving around a solid iron inner core produces Earth’s magnetic field.
Differences in temperature, pressure and composition within the outer core cause convection currents in the molten metal as cool, dense matter sinks whilst warm, less dense matter rises. The Coriolis force, resulting from the Earth’s spin, also causes swirling whirlpools. This flow of liquid iron generates electric currents, which in turn produce magnetic fields. Charged metals passing through these fields go on to create electric currents of their own, and so the cycle continues. This self-sustaining loop is known as the geo-dynamo.

17. Earth’s chemical & physical composition
Phys Layers Chem Layers
Depth of Each Layer: Depth of Each Layer:
Lith – 100km Crust – 0-100km
Asth – 600km Mantle – km
Meso – 2185km Core – km
Outer – 2270km
Inner – 1216km
= 6371km
% Volume:
Lith – 1.57%
Asth – 9.42%
Meso – 34.30%
Outer – 35.64%
Inner – 19.09%
= %

18. The Earth’s Crust, Lithosphere, and Asthenosphere
Mesosphere
Crust
Lithosphere
Mantle
Asthenosphere
Mesosphere

19. 2. What layers of physical structure make up the mantle?
DO NOW: Discuss with a partner & record answers on your PPT Notes Sheet
1. What layer of physical structure contains all of the tectonic plates?
2. What layers of physical structure make up the mantle?
3. What layers of composition make up the lithosphere?
1 – Lithosphere
2 – Lithosphere, Asthenosphere, Mesosphere
3 – Crust & Mantle

20. Differences in Tectonic Plates
Some plates have:
an entire continent and oceanic crust
only oceanic crust
partial continental & oceanic crust

21. an entire continent and oceanic crust only oceanic crust
Some plates have:
an entire continent and oceanic crust
only oceanic crust
partial continental & oceanic crust
Tectonic plates are not neatly divided along continental lines.
North American plate includes the North American continent, Greenland, and half of Iceland.

22. Tectonic Plates float on top of the asthenosphere in a similar way that ice floats on the surface of water.
Plates cover surface of asthenosphere, touch one another, and move around.
Lithosphere displaces the asthenosphere
Thick tectonic plates (made of cont. crust) displace more than thin plates (made of oceanic crust)

23. Mapping the Earth’s Interior
Seismic waves – vibrations caused by earthquakes.
travel at different speeds
speed depends on density and composition of material
faster through solids
faster through denser rock
slower through liquids

24. Seismographs - measure the times at which different seismic waves arrive and record the differences in their speeds
Scientists use the measurements to calculate the density and thickness of each physical layer of the Earth.